The present invention is in the field of viscosity modifiers and particularly in the area of methods for modifying the viscosity of pharmaceuticals, foods, chemicals, personal care products, processing solutions, textiles and paper products.
Biopolymers have found applications in many industries, including the food, cosmetic, chemical, biochemical, waste treatment and oil industries. The functions of a biopolymer, such as water holding capacity, moisturizing effect, thickening, lubrication, adhesion and shape retention, are the result of its fundamental properties under specific conditions. The microbial polysaccharide currently having the most commercial significance due to its unique rheological properties is xanthan.
Another microbial polysaccharide, produced by the organism Zoogloea ramigera, has a proposed structure similar to xanthan gum. Z. ramigera is a gram-negative, rod-shaped, floc-forming, single polar flagellated, obligate aerobe found in aerobic waste treatment facilities and natural aquatic habitats, growing on a variety of carbon and nitrogen sources. It is distinguished from other gram-negative pseudomonads by the presence of an exocellular polymer which causes flocculation and occurs, in some strains, such as Z. ramigera 115, as a zoogloeal or capsule-like matrix.
In nature, the exocellular polymer, Zooglan, a highly branched heteropolysaccharide composed of glucose and galactose in a probable molar ratio of approximately 2:1 with a molecular weight of approximately 10.sup.5 -10.sup.7, is thought to function to concentrate nutrients around the cell flocs enabling them to grow in nutrient deficient environments. Negatively charged carboxyl groups of pyruvate moieties are thought to be primarily responsible for the biopolymer's high affinity for heavy metal ions, such as Cu.sup.++, Co.sup.++, Fe.sup.++, Zn.sup.++, and Ni.sup.++.
It is therefore an object of the present invention to provide a method to utilize the high molecular weight polysaccharide Zooglan as a viscosity modifying agent, drag reducing agent, stabilizer and gellant.
It is a further object of the invention to provide a method for using the polysaccharide Zooglan as a surface modifying agent, for use in flocculation and precipitation, and as a network structure forming agent.